The present invention relates to a combination lock with several encoding buttons to be used for locking containers, boxes or the like, and including a latch movable in between two terminal positions; the latch has a plate which carries a particular number of locking pins cooperating with a corresponding number of rotatable locking disks which in turn are controlled by the encoding buttons. Moreover, a common readjustment or encoding release slide is provided for decoupling the encoding buttons and the locking disks.
U.S. Pat. No. 3,053,071 discloses a device for adjusting the locking and opening conditions for a strong box or the like, using permutation locks with several adjustable disks which are associated with axially displaceable locking disks. The engagement of the locking disks with the adjusting disks is releasable for purposes of readjustment towards a different encoding pattern for unlocking. The locking disks are peripherally provided with engagement spaces, which in case of properly adjustment of the device for opening face the scanning or locking fingers of a latching plate. This latching plate is actuated from the outside through a manual device, whereby the scanning or locking finger enters the engagement space of the locking disks. In order to provide for a new encoding, a control plate is provided for being actuated from the outside, and the locking engagement between the locking disks and the adjustment disks can be overcome by means of ball shaped pressure parts.
German Pat. No. 2,918,235 discloses a permutation lock which can be regarded a development arising from the U.S. patent discussed earlier. This permutation lock does not use a control plate provided just for purposes of re-encoding the lock. Rather, the latching plate in the latter patent is constructed so that it does not only provide a scanning function, but also the function of a locking member for purposes of re-encoding. The latching plate is punched in such a manner that in case of an undercut engagement a rather larger areal, crescent shaped, raised locking zone is established. The latching plate moreover is provided with three locking fingers which, in the case of correct positioning, engage the detent or spaces of the three locking disks. Since the axes of the locking disk are arranged along one line, and since the latching plate is pivotable about an axle pin having a particular distance from the aforementioned straight line, it develops that the turning circles of the locking fingers are differently large. In the case of a locked lock, and in case of a slight load on the handle to adjust the trap disk, a locking finger will slide on the locking disk. Thus, with a "fine feel", one can in fact scan the position of the detents. Through repetition of that kind of probing at the next disk, one can in fact lift the secret of the encoding without any damage to the lock, and the lock can thus be opened and reclosed without a trace.